CN108957963A - A kind of method that substrate is polished in photoetching process - Google Patents

Abstract

The invention discloses a kind of methods polished in photoetching process to substrate, substrate is received from the first processing equipment, wherein structure has been formed on the substrate in the first processing equipment, photoetching process is executed on the received substrate of institute, photoetching process, which is included under optical condition, exposes substrate, it further include the back side that substrate is polished before exposure base, wherein polishing is configured as the shape characteristic of removal substrate back or removes pollutant from the back side of substrate, structure i) is being formed on substrate, and ii) substrate exposure between period during, substrate does not suffer from cleaning procedure.Method of the invention can be suitable for the high efficiency of photoetching process and reduce cost.

Description

A kind of method that substrate is polished in photoetching process

Technical field

The present invention relates to the sides polished in Photolithography Technology field more particularly to a kind of photoetching process to substrate Method.

Background technique

Photoetching process can be used for being formed desired pattern on a semiconductor substrate, and photoetching process can be used for such as integrated circuit (IC) patterned devices (such as mask or mask) can be used in the manufacture IC using lithography system to produce in manufacture The circuit pattern that life will be formed in the single layer of IC, the pattern can be transferred to the target part of substrate (for example, silicon wafer), Wherein the target part of substrate may include a part of device, a device or multiple devices, transfer pattern may include by Pattern is imaged onto the radiation sensitive material layer (for example, resist) of arrangement on substrate.

Technical solution

The invention mainly solves the technical problem of providing a kind of method polished in photoetching process to substrate, the party Method includes: to receive substrate from the first processing equipment, and the first processing equipment forms structure on substrate；And in the received substrate of institute Upper execution photoetching process, photoetching process include: substrate to be exposed under optical condition, and substrate is polished before exposure base The back side, polishing are configured to remove the shape characteristic of substrate back or remove pollutant from the back side of substrate, wherein i) in base Structure and ii are formed on plate) during period between the exposure of substrate, the back side of substrate does not suffer from cleaning procedure.

Further, wherein the exposure of substrate is executed by exposure tool, and photoetching process further includes being located in the surface of substrate In the depth of focus of exposure tool and the polishing of back surface of the wafer is configured as reducing the substrate surface being located at except the depth of focus Region quantity.

Further, wherein the exposure of substrate is executed by exposure tool, and the polishing at the back side of substrate is executed by polishing machine, and Photoetching process further include: provide the pre-exposure light processing of substrate in rail system before substrate exposure, and in substrate exposure The post-exposure processing of substrate is provided in substrate system later.

The beneficial effects of the present invention are:

The method polished in a kind of photoetching process of the invention to substrate can be suitable for the high efficiency of photoetching process With reduce cost.

Detailed description of the invention

Fig. 1 is the block diagram that example system for processing a substrate is described according to some embodiments.

Embodiment

The preferred embodiments of the present invention will be described in detail below, so that advantages of the present invention and feature can be easier to It is readily appreciated by one skilled in the art, so as to make a clearer definition of the protection scope of the present invention.

Fig. 1 is the block diagram 100 described according to some embodiments for handling the example system of substrate 102, in the example of Fig. 1 In, substrate 102 can receive at the first processing equipment 104, and the first processing equipment 104 may include various types of partly leading Body processing equipment.For example, the first processing equipment 104 may include settling chamber, etching machines, semiconductor growing room etc., at first Managing equipment 104 may include settling chamber, which may be configured to form structure on substrate 102, be set by the first processing Standby 104 structures that are formed on substrate 102 may include various forms, for example, plane layer or including etching area or feature one A or multiple layers, after the processing of the first process equipment 104, can receive at photoetching on-line machining tool 108 has shape At the substrate 106 of structure on it, photoetching on-line machining tool 108 can be configured as to be docked in the structure being formed on The substrate of receipts executes photoetching process.Photoetching process can be executed by including the equipment of photoetching on-line machining tool 108, can To include scanner 118, rail system 112 and entire polished backside machine 110, although scanner 118, rail system 112 and whole A polished backside machine 110 can be portrayed as in the example of Fig. 1 to be integrated in lithographic printing on-line machining tool 108, at other In example, the component of equipment 110,112,118 can be with physical separation.Scanner 118 may include exposure tool, the exposure work Tool is configured as the exposure substrate 106 under optical condition, for example, in a lithographic process, photoresist can be applied to lining On bottom 106, then substrate 106 can be exposed to strong ultraviolet (UV) light, the exposure executed by scanner 118 by scanner 118 Light may involve the use of mask or mask, so that only exposing some regions of photoresist, be exposed to purple in scanner 118 Outer light can cause the chemical change in photoresist, this may allow some photoresists to remove by developer solution It goes.Rail system 112 may include i) for executing the equipment 114 and ii of the pre-exposure light processing of substrate 106) for executing lining The equipment 116 of the post-exposure processes at bottom 106.For example, equipment 114 may include the work being applied to resist layer on substrate 106 Tool, and equipment 116 may include the tool of the resist of exposure after executing exposure in scanner 118.Rail system 112 Other aspects can be more fully described below in reference to figure, as shown in Figure 1, photoetching on-line machining tool 108 can be into one Step includes entire polished backside machine 110, and entire polished backside device 110 can be configured as in substrate 106 on scanner 118 The back side of substrate 106 is polished before exposure, entire polished backside machine 110 can be configured as the ground on removal 106 back side of substrate Shape feature (for example, roughness or other scramblings), so as to improve the flatness at the back side.Entire polished backside machine 110 Also it can be configured as the pollution at removal 106 back side of substrate, this can also improve the flatness at the back side.By entire polished backside machine The improvement of the flatness at the back side of 110 substrates 106 enabled can contribute to prevent the defocus occurred on scanner 118 from exposing Light.It may need to carry out accurate wafer orientation on scanner 118 in the exposure of the substrate 106 on scanner 118, accurately Wafer orientation may include being located in substrate 106 on the direction vertical with the surface of substrate 106, positioning in this direction Within the depth of focus for the exposure tool that the surface that can permit substrate 106 is located in scanner 118.When substrate 106 is exposed to When the exposure light from the direction in scanner 118, the distance between substrate 106 and exposing light beam source may be controlled to focusing System has a significant impact.The surface of substrate 106 all may cause scattered from any deviation of the upright position of required upright position exposure Burnt and photolithographic structures quality reduce, and the features of terrain at the back side of substrate 106 can cause to deviate the correct vertical of 106 surface of substrate Position.For example, substrate 106 can have in pre-treatment step (for example, the processing step executed in the first processing equipment 104) It may be not intended to the microcosmic protrusion (for example, scrambling, roughness, pollution etc.) generated.This scrambling at 106 back side of substrate The flatness that 106 back side of substrate may be deteriorated with features of terrain, when substrate 106 is shelved on the wafer chuck of scanner 118, The flatness of deterioration may cause dislocation of the surface of substrate 106 on the direction perpendicular to substrate surface.Therefore, possibility is defocused Occur on scanner 118, although the substrate 106 that can be supported by wafer chuck positioning correcting appropriate by wafer chuck The whole deviation of height, but the local misalignment of substrate location caused by the scrambling and features of terrain at the back side of substrate 106 It may not be to correct in this way.For example, may be led if substrate 106 has micro-protuberance on the back side of substrate 106 Cause the slightly raised regional area compared with other regions on the surface of substrate 106.In the region far from microcosmic height, substrate 106 can partially deform, this may cause these regions and is directly contacted with wafer chuck (that is, the region far from microcosmic height is not It increases).In this way, caused by the regional area of defocus may be the scrambling and features of terrain as 106 back side of substrate, It can be located at except the depth of focus of scanner 118 on the surface of the regional area defocused, substrate 106, scrambling and landform Feature can be detected by focal beam spot monitor 120, can be used as a part of lithographic printing on-line machining tool 108.It is burnt Point position monitor 120 can detecte the height change (for example, peak value) in wafer map, which may be by substrate 106 or the pollution on wafer chuck or it is irregular caused by, wherein height change may cause exposure out of focus.Focal position monitoring Device 120 can produce " FSM " value, and the FSM value on a certain threshold value (for example, FSM > 0.04) may cause chip and be lost It abandons.

Various methods have been proposed to solve the problems, such as the scrambling, features of terrain and pollutant at 106 back side of substrate, In alternative system, before photoetching process, various cleaning procedures can be used to clean the back side of substrate 106.For example, In one alternative system, the washer cleaning procedure and the back side/beveling wafer cleaning procedure of photoetching process execution can be used Handle the back side and inclined-plane of substrate 106.However, such cleaning procedure cannot sufficiently remove 106 back side of substrate scrambling, Features of terrain and pollutant, and cleaning procedure may result in additional processing step and additional equipment, and this may be not It is desired.In addition, cleaning procedure may cause other problems, for example, cleaning procedure may cause to damage to the front side of substrate 106 It is bad.In another example, the selectivity for cleaning process may be suboptimum, and the second choice of opimization may cause cleaning procedure not only The pollutant and scrambling on the back side are removed, and removes the part of substrate 106 and/or the structure formed thereon, this may It is undesirable.In the example system of Fig. 1, cleaning procedure may not be used, specifically, in one example, in I) the The formation of the structure on substrate 102 in one processing equipment 104 and II) 106 period of substrate is exposed on scanner 118, it can not Cleaning process can be used.On the contrary, in the example of fig. 1, entire polished backside machine 110 is desirably integrated into lithography tool 108, and And the back side for polishing substrate 106, scrambling, features of terrain and pollutant, removal scrambling, landform are special to remove Pollutant of seeking peace can help to reduce or eliminate above-mentioned local out-focus region, and the flat substrate for allowing to have lower FSM value 106, therefore, the polishing at the back side of substrate 106 can be configured as the depth of focus for reducing the exposure tool for being located at scanner 118 Except substrate 106 surface regional area.

The sequencing of above embodiments is not only for ease of description, represent the advantages or disadvantages of the embodiments.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although Present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: it still may be used To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features； And these are modified or replaceed, technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution spirit with And range.

Claims (3)

1. a kind of method polished in photoetching process to substrate, which is characterized in that this method comprises: from the first processing equipment Substrate is received, the first processing equipment forms structure on substrate；And

Execute photoetching process on the received substrate of institute, photoetching process include: substrate is exposed under optical condition, and

The back side of substrate is polished before exposure base, polishing is configured to remove the shape characteristic of substrate back or from substrate The back side removes pollutant,

Wherein, structure and ii i) are being formed on substrate) during period between the exposure of substrate, the back side of substrate is not Undergo cleaning procedure.

2. the method polished in a kind of photoetching process according to claim 1 to substrate, it is characterised in that: wherein serve as a contrast The exposure at bottom is executed by exposure tool, and photoetching process further includes that the surface of substrate is located in the depth of focus of exposure tool, And the polishing of back surface of the wafer is configured as reducing the region quantity for the substrate surface being located at except the depth of focus.

3. the method polished in a kind of photoetching process according to claim 1 to substrate, it is characterised in that: wherein base The exposure of plate is executed by exposure tool, and the polishing at the back side of substrate is executed by polishing machine, and photoetching process further include: in substrate The pre-exposure light processing of substrate is provided in rail system before exposure, and provides lining in substrate system after substrate exposure The post-exposure at bottom is handled.